Applications such as electronic communication and navigation require precise determination of receiver location and clock synchronization between receivers. Receiver locations can be calculated using GPS or any number of traditional distance-measuring, surveying, or navigation techniques. However, these techniques all require extra systems or devices to take measurements of the antenna locations.
The problem of clock synchronization occurs because any two time-keeping devices, whether mechanical, crystal, electronic, or atomic, will always eventually diverge and disagree about the current time until they are re-synchronized. This disagreement about time may only be in the range of tens-of-nanoseconds per day for atomic clocks. However, even a tens-of-nanoseconds synchronization error may be too great for certain applications. Synchronization at the nanosecond ranging is currently achieved using methods such as satellites, Ethernet Precise Time Protocol, and line-of-sight RF synchronization. Using satellites such as GPS for time-synchronization has disadvantages because satellite signals are easily blocked by terrain, jammed, or spoofed. Precise Time Protocol over Ethernet requires a deterministic, symmetric path length between the two clock systems, which is not guaranteed by any Ethernet or wireless network. Line-of-Sight RF synchronization requires a clear line of sight between the two devices, which is hard to obtain in real-world environments.
Accordingly, there is a need for an improved system and method that provides for precise receiver location and clock synchronization that does not require additional devices or suffer from the drawbacks discussed above.